This invention relates generally to the field of medical devices and more particularly to electrosurgical cutting/coagulating instruments that can be specifically adapted for use in laparoscopic, endoscopic and open surgery surgical procedures.
The principle of applying electrical current to living being tissue for the purposes of coagulating a bleeding organ or tissue, or for cutting tissue or an organ, is well-known in the art. By passing a certain level of electrical current through a tissue/organ, a coagulation of a bleeding area is accomplished. If the electrical current level is substantially increased, the passage of that higher level current acts to physically sever tissue. Many surgical devices incorporate these electrical cutting and/or coagulating features, such as insulated forceps, biopsy devices and clamping devices.
One well-known type of surgical device that permits a more focused application of electrical cutting and/or coagulating to living being tissue is generally referred to as an electrosurgical instrument, or more commonly referred to as a xe2x80x9cBoviexe2x80x9d. This type of instrument usually comprises an elongated single member having an electrically active tip. The instrument has the general appearance of a pen/pencil with a tapered tip that can be positioned directly onto the tissue being cauterized or cut. The electrosurgical instrument is electrically coupled to the power side of a power supply while the patient is positioned on a conductive plate electrically coupled to the ground of the power supply; the current path is formed from the power source, through the electrosurgical instrument, through the tissue being cut/coagulated and then into the conductive plate. Examples of these types of electrosurgical instruments are shown in U.S. Pat. Nos. 4,911,159 (Johnson et al.); U.S. Pat. No.5,035,695 (Weber, Jr. et al.); U.S. Pat. No. 5,098,430 (Fleenor); U.S. Pat. No. 5,376,089 (Smith); U.S. Pat. No. 5,234,429 (Goldhaber); U.S. Pat. No. 5,484,434 (Cartmell et al.); U.S. Pat. No. 5,626,577 (Harris); U.S. Pat. No. 5,800,431 (Brown); U.S. Pat. No. 5,807,392 (Eggers); U.S. Pat. No. 5,951,548 (DeSisto et al.); U.S. Pat. No. 5,951,551 (Erlich). In some cases, a pair of opposing jaws can be used at the working end instead of a single member, such as that disclosed in U.S. Pat. No. 4,051,855 (Schneiderman).
In other cases, a bipolar configuration of the electrosurgical instrument is used whereby the flow of current is confined between a pair of electrodes at the working end of the electrosurgical instrument, rather than through the patient""s body into a conductive plate. An example of such a bipolar configuration is shown in U.S. Pat. No. 5,573,535 (Viklund).
However, many of these electrosurgical instruments suffer from, among other things, the inadvertent application of a cutting current when only a coagulation current is desired, or vice versa. Furthermore, there is no way of providing the surgeon operating the instrument to have some sort of automatic feedback about what level of current is about to be applied. In addition, the positioning of the electrically-active tip of the electrosurgical instrument against the tissue does not always provide a precise application of the current to the tissue. Thus, there remains a need for an electrosurgical instrument that minimizes the chance of the inadvertent application of cutting or coagulating current to tissue, as well as minimizing the application of electrical and thermal contact of the electrically-active tip to surrounding tissue while providing the surgeon with automatic feedback about what level of current is about to be applied.
An apparatus for cutting and coagulating tissue during surgery of a living being while minimizing electrical and thermal contact of the apparatus with surrounding tissue. The apparatus is coupled to a power supply and wherein the living being is positioned on a conductive plate that is also coupled to the power supply. The apparatus comprises: an elongated body portion having a working end for alternately delivering a coagulation current to tissue through a first portion of the working end and for delivering a cutting current to tissue through a second portion of the working end and wherein the elongated body portion is electrically insulated except for the first portion and the second portion; the first portion comprises a tapered surface that forms the extreme end of the working end of the apparatus and wherein the first portion is electrically conductive and has an aperture therein; the second portion comprises an electrically conductive element having a tapered tip; the first portion and the second portion are movably coupled to each other so that the tapered tip can be positioned externally of the first portion or positioned within the first portion through the aperture; the second portion is electrically enabled whenever the second portion is positioned externally of the first portion while the first portion remains electrically disabled, defining a first apparatus state; wherein the first portion is electrically enabled whenever the second portion is positioned within the first portion and the second portion remains electrically disabled, defining a second apparatus state; and a switch for electrically energizing only the first portion in the first apparatus state when the switch is depressed and for electrically energizing only the second portion in the second apparatus state when the switch is depressed.
A method for cutting and coagulating tissue during surgery of a living being that is positioned on a conductive plate which is connected to a power supply while minimizing electrical and thermal contact of surrounding tissue. The method comprises the steps of: providing an electrosurgical instrument that is completely insulated except for a first and second portion of the working end of the instrument; coupling the instrument to the power supply and electrically enabling one of the portions while electrically disabling the other one of the portions depending on the relative positions of the first and second portions; electrically energizing the electrically enabled portion by a activating a switch to deliver a coagulating current or a cutting current to the tissue.